2bitVV is a re-implementation of svpVV in C++.  Preliminary testing
suggests that it should be about a factor eight faster than svpVV,
which was implemented as a glish script.  Moreover, 2bitVV doesn't
suffer from the memory leakage problems that svpVV had.  Therefore it
should play nicely with other processes running on the same machine.
It should even be possible to run multiple 2bitVV jobs in parallel on
the same machine.

Using 2bitVV is simple.  It accepts UNIX-style options:

$ 2bitVV
usage: 2bitVV [-f|-s] [-H minhst] [-W minwgt] ms

For it to do anything usefil, you'll need to specify the AIPS++
measurement set that is to be Van Vleck corrected:

$ 2bitVV N04L2.ms
Processed 141240/141240 rows.
Flushing... done.

You can specify a weight threshold and a threshold for the
sum-of-highs sampler statistics by using the -W and -H options:

$ 2bitVV -W 0.1 -H 0.01 N04L2.ms
Processed 141240/141240 rows.
Flushing... done.

In this particular invocation of 2bitVV the specification of the
thresholds isn't particularly useful since 0.1 and 0.01 happen to be
the defaults.

Note that the program will complain and refuse to run if you specify
insane values for any of the thresholds.  If you think you know
better, you can use the -f option to make it run anyway.

2bitVV will report the progress it's making, but if you don't want
that you can use the -s option.

As before it is probably a good idea to keep a copy of the origional
measurement set just in case things crash halfway through the
correction process.

Please report any problems to Mark Kettenis <kettenis@jive.nl>.
